This invention relates to a motor control center (MCC) communication system. More particular, this invention relates to a MCC communication system that employs a centralized control configuration for controlling buckets within a MCC of the MCC communication system.
A MCC manages the application of electrical power to motors. The MCC is typically connected to a main power line that feeds three-phase ac power into the MCC. An example MCC is a multi-compartment steel enclosure with a bus system to distribute electrical power on a common bus to a plurality of motor control units mountable within the compartments. These motor control units are referred to as “buckets”. These buckets include various electronic components such as magnetic contactors, overload relays, and circuit breakers, for example. In a conventional bucket, communication is built into the electronic components. For example, the overload relay may include a communication port for communicating current and voltage status along with motor actuating capability. In a conventional MCC, a plurality of the buckets are operatively connected and controlled via control wiring of approximately 120V or higher to a remote panel. This often requires hundreds of feet of control wiring in conduit. During the course of operations, controls within the buckets may need to be upgraded. Thus, in order to upgrade the controls, the control wiring may have to be changed and additional wiring may be required which may result in crowded wire passages within conduit, and increased installation and maintenance costs.
While existing MCC communication systems are suitable for their intended purpose, there is a need for an improved MCC communication system that allows for flexibility in expanding an installed MCC communication system, and also utilizes low voltage control wiring, to thereby reduce manufacturing and maintenance costs for the system.